Pressure responsive apparatus
First Claim
1. Apparatus suitable for use as a pressure standard, comprising a reference container arranged, in use, to have a predetermined orientation and to be charged with a liquid whereby the pressure at a port in the lower part of the container is at a predetermined value, and wherein the container is sealed at an upper part by a closure member having characteristics such that the space above the liquid within the container is isolated from the external environment while being maintained at a pressure substantially equal to the pressure of the external environment.
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Accused Products
Abstract
Apparatus suitable for use as a hydrostatic pressure standard comprises a vertically-mounted container charged with a predetermined amount of a liquid having a low-vapor pressure, such as an hydraulic oil, to provide a predetermined pressure head at a port at the lower end of the container. The container is provided at its upper end with a closure in the form of a variable volume device which is so arranged that the pressure in the space within the container above the liquid is maintained substantially equal to the external, e.g. atmospheric pressure. A system for determining the mass of a liquid in a tank and embodying two such pressure standards is also described.
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Citations
24 Claims
- 1. Apparatus suitable for use as a pressure standard, comprising a reference container arranged, in use, to have a predetermined orientation and to be charged with a liquid whereby the pressure at a port in the lower part of the container is at a predetermined value, and wherein the container is sealed at an upper part by a closure member having characteristics such that the space above the liquid within the container is isolated from the external environment while being maintained at a pressure substantially equal to the pressure of the external environment.
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9. Apparatus suitable for use as a hydrostatic pressure standard comprising a reference container arranged, in use, to be mounted with a predetermined orientation and to be charged with a predetermined mass of liquid to provide a predetermined pressure head at a port at or near its lower end, and sealed at its open, upper end by a closure member having characteristics such that a change in the volume of the space within the container above the liquid does not substantially affect the pressure at said port.
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10. A pressure monitoring system including:
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a source of pressure to be monitored; transducer means responsive to pressures within a range defined by a minimum pressure and a maximum pressure, said transducer means having a calibration curve and providing an output signal relating to the calibration curve; pressure standard means for providing a standard of pressure at substantially one of the minimum pressure and the maximum pressure; means for selectively coupling the transducer means to the pressure standard means and the source of pressure to be monitored; and processing means responsive to the output signal of the transducer means when coupled to the pressure standard means and the source to provide an adjusted output signal representative of the pressure to be monitored. - View Dependent Claims (11, 12, 13, 14, 15)
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16. A pressure monitoring system comprising:
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a source of pressure to be monitored; transducer means responsive to pressures within a range defined by a minimum pressure and a maximum pressure; first means for providing a standard of pressure of substantially one of the minimum pressure and the maximum pressure; a reference container included in the first means and having a port located near a lower end thereof and a closure member located near an upper end thereof, said container being adapted to be charged with a predetermined mass of a fluid and said closure member having properties such that a change in the pressure in the space above the fluid in the container does not affect the pressure at the port; and second means for selectively coupling the transducer means to the first means for calibrating the transducer means at the one pressure and for coupling the transducer means to the source for determining the pressure to be monitored.
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17. A pressure monitoring system comprising:
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a source of pressure to be monitored; transducer means responsive to pressures within a range defined by a minimum pressure and a maximum pressure; first means for providing a standard of pressure of substantially the maximum pressure defining the range of the transducer means; third means for selectively coupling the transducer means to the first means for calibrating the transducer means at the maximum pressure; fourth means for selectively coupling the transducer means to the second means for calibrating the transducer means at the minimum pressure; and means for coupling the transducer means to the source for determining the pressure to be monitored.
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18. A pressure monitoring system comprising:
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a source of pressure to be monitored; the source including a tank, a first liquid disposed within the tank and having a hydrostatic pressure to be monitored, and a first gas disposed within the tank above the first liquid in the tank; transducer means responsive to pressures within a range defined by a minimum pressure and a maximum pressure; first means for providing a standard of pressure of substantially one of the minimum pressure and the maximum pressure; the first means including a reference container, a second liquid disposed within the reference container, and a second gas disposed within the reference container above the second liquid in the reference container; second means coupled between the tank and the reference container for maintaining the pressure of the first gas substantially equal to the pressure of the second gas; and third means for selectively coupling the transducer means to the first means for calibrating the transducer means at the one pressure and for coupling the transducer means to the source for determining the pressure to be monitored. - View Dependent Claims (19, 20)
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21. A pressure monitoring system including:
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a source of pressure to be monitored, the source including a first liquid disposed in a tank and a first gas disposed above the first liquid in the tank; transducer means responsive to pressures within a range defined by a minimum pressure and a maximum pressure, said transducer means having a calibration curve and providing an output signal relating to the calibration curve; pressure standard means for providing a standard of pressure at substantially one of the minimum pressure and the maximum pressure, the pressure standard means including a reference container, a second liquid disposed within the reference container, a second gas disposed within the reference container, and means coupled between the tank and the reference container for maintaining the pressure of the first gas substantially equal to the pressure of the second gas; means for selectively coupling the transducer means to pressure standard means and the source of pressure to be monitored; and processing means responsive to the output signal of the transducer means when coupled to the pressure standard means and the source to provide an adjusted output signal representive of the pressure to be monitored. - View Dependent Claims (22)
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23. A pressure monitoring system comprising:
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a source of pressure to be monitored; transducer means having a calibration curve and being responsive to pressures within a range defined by a minimum pressure and a maximum pressure; first means for providing a standard of pressure of substantially one of the minimum pressure and the maximum pressure; second means for selectively coupling the transducer means to the first means for calibrating the transducer means at the one pressure and for coupling the transducer means to the source for determining the pressure to be monitored; and data processing means coupled to the transducer means for storing signals representative of the calibration curve of the transducer means for compensating for deviations of the output of the transducer means when the transducer means is coupled to the source for measurement of the pressure to be monitored.
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24. A pressure monitoring system including:
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a source of pressure to be monitored; transducer means responsive to pressures within a range defined by a minimum pressure and a maximum pressure, said transducer means having a calibration curve and providing an output signal relating to the calibration curve; pressure standard means for providing a standard of pressure at substantially one of the minimum pressure and the maximum pressure; means for selectively coupling the transducer means to the pressure standard means and the source of pressure to be monitored; processing means responsive to the output signal of the transducer means when coupled to the pressure standard means and the source to provide an adjusted output signal representative of the pressure to be monitored; and means included in the processing means for storing values representative of the calibration curve of the transducer means, said processing means being responsive to the output signal of the transducer means when coupled to the pressure standard means for providing adjusted stored values of the calibration curve of the transducer means and being responsive to the transducer means when coupled to the source to select from among the adjusted stored values the adjusted output signal representative of the pressure to be monitored.
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Specification